The adroit and daring officer who commanded the Roman vanguard nevertheless set sail with his troops. But the Carthaginians warned the Roman vessels to retire, and even made some of them prizes; these, however, the Carthaginian admiral, remembering his strict orders to give no pretext for the outbreak of hostilities, sent back to his good friends on the other side of the straits. It almost seemed as if the Romans had compromised themselves as uselessly before Messana, as the Carthaginians before Tarentum. But Claudius did not allow himself to be deterred, and on a second attempt he succeeded in landing. Scarcely had he arrived when he called a meeting of the citizens; and, at his wish, the Carthaginian admiral also appeared at the meeting, still imagining that he should be able to avoid an open breach. But the Romans seized his person in the assembly itself; and Hanno and the Phoenician garrison in the citadel, weak and destitute of a leader, were pusillanimous enough, the former to give to his troops the command to withdraw, the latter to comply with the orders of their captive general and to evacuate the city along with him. Thus the tete de pont of the island fell into the hands of the Romans. The Carthaginian authorities, justly indignant at the folly and weakness of their general, caused him to be executed, and declared war against the Romans. Above all it was their aim to recover the lost place. A strong Carthaginian fleet, led by Hanno, son of Hannibal, appeared off Messana; while the fleet blockaded the straits, the Carthaginian army landing from it began the siege on the north side. Hiero, who had only waited for the Carthaginian attack to begin the war with Rome, again brought up his army, which he had hardly withdrawn, against Messana, and undertook the attack on the south side of the city.

But meanwhile the Roman consul Appius Claudius Caudex had appeared at Rhegium with the main body of his army, and succeeded in crossing on a dark night in spite of the Carthaginian fleet. Audacity and fortune were on the side of the Romans; the allies, not prepared for an attack by the whole Roman army and consequently not united, were beaten in detail by the Roman legions issuing from the city; and thus the siege was raised. The Roman army kept the field during the summer, and even made an attempt on Syracuse; but, when that had failed and the siege of Echetla (on the confines of the territories of Syracuse and Carthage) had to be abandoned with loss, the Roman army returned to Messana, and thence, leaving a strong garrison behind them, to Italy. The results obtained in this first campaign of the Romans out of Italy may not quite have corresponded to the expectations at home, for the consul had no triumph; nevertheless, the energy which the Romans displayed in Sicily could not fail to make a great impression on the Sicilian Greeks. In the following year both consuls and an army twice as large entered the island unopposed. One of them, Marcus Valerius Maximus, afterwards called from this campaign the "hero of Messana" (Messalla), achieved a brilliant victory over the allied Carthaginians and Syracusans. After this battle the Phoenician army no longer ventured to keep the field against the Romans; Alaesa, Centuripa, and the smaller Greek towns generally fell to the victors, and Hiero himself abandoned the Carthaginian side and made peace and alliance with the Romans (491). He pursued a judicious policy in joining the Romans as soon as it appeared that their interference in Sicily was in earnest, and while there was still time to purchase peace without cessions and sacrifices. The intermediate states in Sicily, Syracuse and Messana, which were unable to follow out a policy of their own and had only the choice between Roman and Carthaginian hegemony, could not but at any rate prefer the former; because the Romans had very probably not as yet formed the design of conquering the island for themselves, but sought merely to prevent its being acquired by Carthage, and at all events Rome might be expected to substitute a more tolerable treatment and a due protection of commercial freedom for the tyrannizing and monopolizing system that Carthage pursued. Henceforth Hiero continued to be the most important, the steadiest, and the most esteemed ally of the Romans in the island.

The Romans had thus gained their immediate object. By their double alliance with Messana and Syracuse, and the firm hold which they had on the whole east coast, they secured the means of landing on the island and of maintaining - which hitherto had been a very difficult matter - their armies there; and the war, which had previously been doubtful and hazardous, lost in a great measure its character of risk. Accordingly, no greater exertions were made for it than for the wars in Samnium and Etruria; the two legions which were sent over to the island for the next year (492) sufficed, in concert with the Sicilian Greeks, to drive the Carthaginians everywhere into their fortresses. The commander-in-chief of the Carthaginians, Hannibal son of Gisgo, threw himself with the flower of his troops into Agrigentum, to defend to the last that most important of the Carthaginian inland cities. Unable to storm a city so strong, the Romans blockaded it with entrenched lines and a double camp; the besieged, who numbered 50,000 soon suffered from want of provisions. To raise the siege the Carthaginian admiral Hanno landed at Heraclea, and cut off in turn the supplies from the Roman besieging force. On both sides the distress was great. At length a battle was resolved on, to put an end to the state of embarrassment and uncertainty. In this battle the Numidian cavalry showed itself just as superior to the Roman horse as the Roman infantry was superior to the Phoenician foot; the infantry decided the victory, but the losses even of the Romans were very considerable. The result of the successful struggle was somewhat marred by the circumstance that, after the battle, during the confusion and fatigue of the conquerors, the beleaguered army succeeded in escaping from the city and in reaching the fleet. The victory was nevertheless of importance; Agrigentum fell into the hands of the Romans, and thus the whole island was in their power, with the exception of the maritime fortresses, in which the Carthaginian general Hamilcar, Hanno's successor in command, entrenched himself to the teeth, and was not to be driven out either by force or by famine. The war was thenceforth continued only by sallies of the Carthaginians from the Sicilian fortresses and their descents on the Italian coasts.

In fact, the Romans now for the first time felt the real difficulties of the war. If, as we are told, the Carthaginian diplomatists before the outbreak of hostilities warned the Romans not to push the matter to a breach, because against their will no Roman could even wash his hands in the sea, the threat was well founded. The Carthaginian fleet ruled the sea without a rival, and not only kept the coast towns of Sicily in due obedience and provided them with all necessaries, but also threatened a descent upon Italy, for which reason it was necessary in 492 to retain a consular army there. No invasion on a large scale occurred; but smaller Carthaginian detachments landed on the Italian coasts and levied contributions on the allies of Rome, and what was worst of all, completely paralyzed the commerce of Rome and her allies. The continuance of such a course for even a short time would suffice entirely to ruin Caere, Ostia, Neapolis, Tarentum, and Syracuse, while the Carthaginians easily consoled themselves for the loss of the tribute of Sicily with the contributions which they levied and the rich prizes of their privateering. The Romans now learned, what Dionysius, Agathocles, and Pyrrhus had learned before, that it was as difficult to conquer the Carthaginians as it was easy to beat them in the field. They saw that everything depended on procuring a fleet, and resolved to form one of twenty triremes and a hundred quinqueremes. The execution, however, of this energetic resolution was not easy. The representation originating in the schools of the rhetoricians, which would have us believe that the Romans then for the first time dipped their oars in water, is no doubt a childish tale; the mercantile marine of Italy must at this time have been very extensive, and there was no want even of Italian vessels of war. But these were war-barks and triremes, such as had been in use in earlier times; quinqueremes, which under the more modern system of naval warfare that had originated chiefly in Cartilage were almost exclusively employed in the line, had not yet been built in Italy. The measure adopted by the Romans was therefore much as if a maritime state of the present day were to pass at once from the building of frigates and cutters to the building of ships of the line; and, just as in such a case now a foreign ship of the line would, if possible, be adopted as a pattern, the Romans referred their master shipbuilders to a stranded Carthaginian penteres as a model No doubt the Romans, had they wished, might have sooner attained their object with the aid of the Syracusans and Massiliots; but their statesmen had too much sagacity to desire to defend Italy by means of a fleet not Italian. The Italian allies, however, were largely drawn upon both for the naval officers, who must have been for the most part taken from the Italian mercantile marine, and for the sailors, whose name (socii navales) shows that for a time they were exclusively furnished by the allies; along with these, slaves provided by the state and the wealthier families were afterwards employed, and ere long also the poorer class of burgesses. Under such circumstances, and when we take into account, as is but fair, on the one hand the comparatively low state of shipbuilding at that time, and on the other hand the energy of the Romans, there is nothing incredible in the statement that the Romans solved within a year the problem - which baffled Napoleon - of converting a continental into a maritime power, and actually launched their fleet of 120 sail in the spring of 494.